Laser printers use a coherent beam of light, hence the term “laser printer,” to expose discrete portions of an image transfer drum thus attracting the printing toner. Toner is a mixture of pigment (most commonly black) and plastic particles. The toner becomes electrostatically attracted to exposed portions of the image transfer drum. The toner transfers to paper, or other medium, as it passes over the rotating image transfer drum. Subsequently, the paper is heated so that the plastic is melted thereby permanently affixing the ink to the paper.
The vast majority of commercially available desktop laser printers include replaceable or removable toner cartridges that incorporate an image transfer drum, a toner tank, and a metering system. A drive mechanism connects to the drum and metering system. Modern toner cartridges often include a variety of sensors that interact with the laser printer to indicate the status of the cartridge. Indications relating to toner level, print quality and general cartridge function are often included as well. A large number of types and sizes of toner cartridges are currently available. The sensing system typically includes an encoder wheel interconnected with a rotating beater blade within a cylindrical toner tank. Movement of the beater blade feeds toner into the metering system. The encoder wheel reports the movement of the beater wheel through the rear housing.
Previously, certain printers in the electro-photography industry have produced inconsistent images as a result of toner particles being unevenly distributed. What is therefore needed is a means of uniformly distributing toner as it leaves the hopper across the toner adder roller, thereby eliminating the clumping of toner particles.